


Unlikely Alliance

by Hertz



Category: ARGONAVIS from BanG Dream! AAside (Video Game)
Genre: Alpha/Beta, Alpha/Beta/Omega Dynamics, Bottom Alpha, Hate Sex, M/M, Some Fluff
Language: English
Status: Completed
Published: 2020-05-24
Updated: 2020-05-24
Packaged: 2021-03-03 00:08:46
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,774
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24355594
Author URL: https://archiveofourown.org/users/Hertz/pseuds/Hertz
Summary: The alpha Kikyou Rio has decided to allow Wataru, a mere beta, to be his mate, for reasons Wataru doesn’t understand.
Relationships: Kikyou Rio/Matoba Wataru
Comments: 2
Kudos: 39
Collections: te leeré luego





	Unlikely Alliance

“I’ll have you know it’s beneath me to be mated to a beta. You should consider this a rare privilege.”

Wataru continues to growl, baring his teeth and snarling, but Rio only tilts his head and smiles, that same calm, infuriating, _condescending_ smile. Wataru knows that smile, he knows the attitude of alphas like Rio.

“What’s the matter?” Rio asks sweetly, so sweetly Wataru just knows it's fake. 

“And I’ll have you know it’s beneath me to be fucked by an arrogant prick like you,” Wataru spits out between clenched fangs.

“Arrogant? What a vile adjective.”

Nevertheless Wataru finds himself gasping as Rio prods lower, running his tan fingertips across his sides. They’re long and slender and agile, and Rio slips his hands underneath Wataru’s suit. Wataru struggles against his strong grasp. He told mother, father, and that damn brother of his he’d agree to this stupid arranged marriage, but that didn’t mean he’d submit so easily. 

Even if that meant the ceremony was over and now he was in Rio’s bed, nothing between them save their clothes.

Rio simply gives a tsk in reply, but his face remains ever calm - and Wataru hates that. He wants to see Rio break his stoic composure, get angry, yell at him, anything to prove that Wataru’s getting under his skin - but the only indicator is Rio’s alpha scent getting slightly stronger, and Rio’s face remains composed, his motions fluid.

“I expected better behaviour from the famed Satozuka clan,” says Rio, staring down at him with slitted red eyes that seem to glow in the low light. “Is this how you treat your superiors?”

“You’re nothing,” Wataru snarls. “You think you’re hot shit, but my brother, our clan heir, he’s an alpha too. And he’s the absolute worst prick I’ve ever had to deal with growing up.”

Rio quirks his eyebrows. “My condolences,” he says simply. “Now let me undress you.”

“Why should I?”

“To keep up the reputation of both of our clans.” Rio cocks his head. “You’re no omega, but they can smell if we’ve had sex, you know, and then what would they say? I’d hate to have gossip spreading about my dear mate - that he wasn't enough to satisfy me, that he wouldn’t yield to an alpha, that he’s stubborn and doesn’t know his place -”

Wataru wants to snarl at him, to swipe at him. “Shut your condescending ass up, and don’t pretend to care about me. You sicken me.”

“But is that a yes?” asks Rio, low voice velvety smooth even now.

“Yes, I’ll fuck myself on your engorged cock. Are you happy now?” Wataru grapples with the buttons on his suit, hands clumsy from anger. Rio is silent, but his glittering ruby eyes signal his approval when Wataru strips himself of the undershirt. The scent of flowers still clings to his pale skin and red hair. 

Rio descends then, hands gliding down Wataru’s supple body from his pecs all the way down to his inner thighs, and Wataru can’t help the shiver his body gives in response. He might not be an omega, but Rio’s experienced hands know exactly where to coax a reaction out of him. And Wataru’s currently thankful for that fact, because now Rio’s alpha scent can’t drive him crazy, won’t make his eyes cross with hormones and heat and blush prettily red like the virgin he is.

Because he’s a beta - nowhere near as powerful as an alpha, nowhere near as desired as an omega. His brother, an alpha, better than him in every way. Then there’s Wataru… his parents’ disappointment and society’s dismissal. Wataru has to wonder - how desperate is the Kikyou clan for a mate, to agree to something like this? To allow their only son, in mated marriage with a beta like Wataru is?

The thought makes a flash of bitterness strike across his heart, and Wataru leans back, allowing Rio to bite the side of his neck roughly. The mating mark. There’s no going back now.

“Why me?” Wataru asks, little louder than a whisper, and Rio stares at him again with those unreadable eyes. Rio’s hand moves up, and belatedly, Wataru realises he’s reaching for his face. Wataru flinches, but Rio’s touch is surprisingly gentle for the experiences they’ve shared so far.

“When your parents sent out letters seeking a suitable mate for you, I couldn’t take my eyes off you.”

Despite himself, Wataru’s heart pounds faster. He manages a weak chuckle. “Flattery won’t get you anywhere.”

“I’m not flattering you,” says Rio with a derisive snort. “You asked, and I answered with proper facts.” He tilts his head then, giving Wataru a challenging gaze. “I hear betas aren’t as good as alphas as etching bite marks on their mates. Let me see you prove them wrong.”

Wataru wishes he could turn around and look at his own neck in the mirror, to give him a gauge, just anything. But he can’t when Rio’s looking at him so expectantly like that. So, with slight hesitation, he leans forward, but Rio pushes him away.

“Do it again. With confidence. Are you not the powerful son of the Satozuka? Act like one.”

The fact that someone believes in Wataru as his own person, even if that someone is Kikyou Rio, to Wataru’s shame, indeed guides a surge of power through his being. With a snarl, Wataru digs his pointed nails into Rio’s shoulders, forcing him forward, biting as hard as he can into tan, soft skin. He feels rather than hears Rio’s sharp intake of breath and his little curse, and Wataru breaks away, panting. He studies the mark even as Rio traces his left hand against it, gauging the depth of it.

Finally satisfied, Rio turns to Wataru and licks his lips, letting his hand trail lower. Wataru almost starts when he realises he’s hard and Rio begins stroking him from the tip down to his sensitive balls. He bites his lip as Rio leans forward to whisper in his ear. “If you’ve got something to prove, then prove it,” he says, twisting his wrist on the upstroke and making Wataru’s toes curl. “Right here, right now.”

Wataru’s lips part to answer, but he finds his breath stolen when Rio kisses the mark on his neck, draws the pale skin into his mouth to tease and suckle. He bucks against Rio’s weight on top of him, finding his wrists pinned to the headboard as Rio works. No one’s ever touched him this way before and Wataru feels a very omega-esque moan slipping out of his mouth as his eyes squeeze shut on instinct.

He finds himself chasing the ghost of Rio’s lips as he pulls away. He realises that Rio is finally casting away his suit top and trousers. And though Rio might be an arrogant asshole, Wataru finds his eyes roaming across the alpha’s tanned body and prominent muscles, his hands aching to touch. Rio turns away to rustle for the lube in his drawer and pours a generous dollop over Wataru’s cock… hang on. _His_ cock?

“Isn’t this _beneath you_?” Wataru hisses, partly from scorn, partly from the smooth way Rio’s hand pumps his cock. “Doesn’t it demean you to have a beta’s cock up your ass, _alpha_?” With the lube, the sensations are enhanced, and Wataru pants as he fights not to come too soon. He’d had his hands on himself before, but not like this, never like this.

“Hm,” Rio bothers to give in response, his tone far too dismissive for Wataru’s liking. But then his hand stills and Rio’s positioning himself above Wataru’s cock. Before Wataru can stop him, his mind blanks out when Rio sinks down on it in one swift motion. The both of them pant, Wataru fighting to control his breathing as Rio’s warm, tight ass clenches around him. It sends slivers of sensation through his cock that makes him let out little moans of pleasure.

“I suppose it would,” Rio finally says between breaths, “If I hadn't been preparing myself all night for this.”

Then Rio lifts his hips up and slams back down, and Wataru finds himself being pulled into the force of the motion. He does his best to ground himself, letting out a moan as Rio continues his relentless assault, his grip on Wataru’s shoulders strong and steady even though sweat plasters his forehead and his dark green hair is finally escaping from the neat style it's been combed into. Wataru sneaks a curious peek at the alpha’s cock, which is starting to knot. Then the pleasure subsides as Rio stops moving and it’s all Wataru can do not to whine in protest.

“What are you waiting for?” Rio asks, because even now he can’t shut the fuck up. “Come on, beta. Show me what you can do with that large cock of yours.”

“It won’t knot,” Wataru grits out.

“Does that matter?” Wataru chokes back a moan as Rio slams his hips down again, grinding his ass against it, and the pleasure threatens to rip through Wataru’s entire being. He twitches in his position, letting out a gasp when Rio’s voice drops an octave lower. “Fuck me, beta. Let go. Show me who you really are.”

And something in Wataru snaps at that. He growls faintly, “Shut up,” and presses his hands against Rio’s hips. Using this to steady himself, Wataru bucks his hips into Rio, searching for that sweet spot inside of him, already guided along by Rio’s previous attempts. Wataru gasps and clutches harder at Rio’s hips at the responding tightness of Rio’s walls, just how perfectly he clenches against his cock.

Wataru forces Rio’s head downwards to clumsily bite at the mark he’s left on Rio’s neck, and Rio obliges, leaning in and closing his eyes in content. He’s still panting harshly, doing his best to follow the harsh pace Wataru has set for them both, sending Wataru’s cock deeper and deeper into Rio with every thrust. Wataru can barely hear anything over the roaring of his own head and Rio’s quick, stuttered breaths.

Rio feels so sinfully good - so hot, so wet, so tight. It makes Wataru slide his cock in and out of Rio’s hole so hard, so fast, that Wataru himself is left gasping for breath. Finally, Wataru knows he’s hit the jackpot when Rio tightens impossibly further around him, that delicious friction coming to a head. Rio is a mess now, blurting out scrambled demands like “Fuck, yes, Wataru, _yes_ , more,” only to let out a moan when Wataru angles his hips and strikes that sweet spot again.

“Not so - ah - talkative now, are you?” Wataru huffs. Intent on not giving Rio the satisfaction of replying, he’s merciless then, chasing the sweet, sweet feeling of Rio’s tight ass clenching around his cock. Wataru emits small hisses and moans of pleasure as he fucks into Rio’s tight heat and Rio moans loudly in his ear just for him when he sucks the skin of his neck just right.

“S-so good,” Wataru finds himself murmuring in a low voice. The sensations are becoming almost too much for him to bear. His hips stutter with every slick slide into Rio’s tight hole, and Rio’s own cock is fattening at the tip. His stomach twists and turns and knots itself inside out. From how Rio’s ass seems to draw him in, his breath catching and moans a wonderful symphony, Wataru just knows he has to be close as well. He can feel just how _hot_ Rio is getting above him. Distantly, he registers the creaks and groans of the alpha’s bed amidst the pounding Rio’s receiving.

Wataru releases his right hand from Rio’s hips to awkwardly stroke the tip of the alpha’s cock, doing his best not to slow his rapid thrusting. Rio utters a string of curses. “Fuck yes, beta… more, _Wataru_ ,” he moans sweetly, the sounds encouraging Wataru not to stop, never to stop. Wataru strokes Rio’s cock best as he’s able, feeling it stir and pulse in his hand all while he thrusts into Rio. Gripping Rio’s side, Wataru feels muscle flex underneath the force of his teeth. He loves the bruises Rio’s iron grip on his shoulders is sure to leave in the morning.

“Fucking - oh, Wataru, you’re exquisite,” moans Rio harshly, gritting his teeth as Wataru curls his hand around the alpha’s cock just right at the same time Wataru thrusts upwards into _that_ spot. Wataru barely realises he’s smirking at that, bringing his alpha to ruin, too busy working on the delectable skin beneath him with his sharp teeth. Actually, Wataru can barely think at this point - everything’s awash in a haze of lust and pure pleasure, and Rio feels so, so fucking _good_.

Wataru’s lost at sea, everything else washed away, replaced by his single-minded possessive desire to own Rio completely. Something sadistic has been awakened inside him, something that wishes to see Rio like this for all eternity. He’s almost unbearably attractive this way - his muscles flexing, eyes screwed shut, dark brows furrowed and a flush visible all over his tanned body. Wataru imagines what Rio’s ass might look like: red, gaping, pounded raw by his cock and no one else’s.

Rio lets out a shuddering gasp as Wataru grinds against that sensitive bundle of nerves inside of him, and Wataru is no better himself - he feels his loins tightening and his head of his cock starting to throb in warning. 

“ _Wataru_ ,” gasps Rio, “Wataru, I’m going t-to… I’m - I’m so _close_.” At that, Wataru circles his thumb at the tip of Rio’s knot as he thrusts upwards one last time, and his alpha comes undone, thick ropes of cum shooting across Wataru’s chest and stomach. The sight is enough to send a bolt of lightning through the knot in Wataru’s stomach, and the intense pressure of Rio’s ass around him, gripping hot and tight, finally becomes too much for Wataru to bear. 

Rio arches his back and Wataru sobs when he finally falls over the edge, the pleasure maddening as he continues pounding Rio’s tight hole. His cock slips in amd out messily, sending sparks of pure pleasure up his spine. Wataru rakes his claws down Rio’s muscled back, tears gathering in the corner of his eyes. It feels so fucking _good_ , so euphoric, like he’s falling apart at the seams.

Finally, Rio collapses on top of him, spent and panting while Wataru tries to remember his own name. It might be forever or a few moments they spend like this, together in comfortable silence for once. Then Rio rolls off Wataru’s chest to the right, lying on his back and staring up at the ceiling. Dazed, Wataru is taking in everything and nothing all at once - the warmth of his mate next to him, the blurry browns and greens of Rio’s bedroom blurring together in his vision, and the hot stickiness he feels all over his body.

At long last, Rio turns on his side, giving Wataru what might be his most genuine smile yet, soft around the edges of his eyes and red eyes glimmering with something yet unknown. “I knew you had it in you, beta.”

“So it’s back to ‘beta’ now, huh?” Wataru rolls his eyes, though this time there’s no real heat in his words. “Could’ve sworn you knew my name. You were moaning it like a complete slut just a while ago.”

“That I was,” acknowledges Rio. “How do you feel, knowing you’ve made an alpha submit?”

Wataru averts his gaze. He’s certain his face is tinged with a telltale blush almost as red as his hair. “I didn’t make you do anything. It was your choice.”

“And you performed admirably, so why is it you doubt yourself so?”

Wataru sighs and reaches for the sheets to cover himself up. “Ugh. Look, I’m…” he hesitates for a long while before he says, “sorry.”

“Whatever for?” asks Rio with a twinkle in his eyes, and Wataru’s _certain_ he’s riling him up on purpose.

“Ugh, jackass, I guess I was just sick of being compared to my brother all the time, and looked down upon by alphas like you. Are you happy now I’ve said that?” Wataru demands.

The next moment, his lips are enveloped in a kiss… and that’s when Wataru realises for all their mating shit going on just now Rio had never tried this. The kiss is warm, soft, and slow, and Wataru has to stop himself from chasing after Rio’s lips when the alpha pulls away.

“I’m very happy indeed,” says Rio, and this time his grin is _unbearably_ smug.


End file.
